EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: AaronB on October 27, 2020, 02:25:09 pm
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I snagged a Tech TE-20D signal generator from a flea market for €10 and want to get it running. It looks pretty clean inside, but probably not wise to plug it in without some preflight checks. The only danger area I see are a couple of 20uF electrolytics, which I will replace. There are a few other ceramics which I could speculatively change but probably not worth it. The resistors look good. Anything else to consider before I fire it up with 100W bulb in the mains supply as the first test?
I'd also like to add a proper earth to the outside case and chassis, will that be a problem?
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Don't know if you had a chance to download the manual, here it is attached.
Looking at the schematic diagram - I would check the transformer primary and secondaries (there are two - one high voltafe 120V and one for filaments 6.3V) with an ohmmeter first. Primary should have a higher resistance than the secondary.
If you have a rheostat, start with lower voltage - I would power it on like that first. If a fuse is blown, try to find out why before replacing it.
Anything you do, PLEASE be careful with the MAINS voltage.
Do not work alone, make sure there is someone else around you when you connect equipment to the mains power with the case open.
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Thanks @lordhex for the manual, the schematic will be very useful. It is actually an EU unit, so it is 230V primary. And I am used to working with mains voltage - just finished dancing around a 2KV supply while fixing my oscilloscope.
Having just removed the 20uF caps, I find they measure at 30uF. Out of spec, but in a good way I guess. Probably worthwhile replacing anyway.